diff --git a/honoka/libhonoka/preeditor.cpp b/honoka/libhonoka/preeditor.cpp
index 076556f..6530b08 100644
--- a/honoka/libhonoka/preeditor.cpp
+++ b/honoka/libhonoka/preeditor.cpp
@@ -415,3 +415,15 @@
 {
     commitString.clear();
 }
+
+
+/*!
+    \fn Honoka::PreEditor::isPrintable(KeyEvent &key)
+ */
+bool Honoka::PreEditor::isPrintable(KeyEvent &key)
+{
+    // �Ȥꤢ����get_ascii_code()��isprint�򤫤��롣
+    if (isprint(key.get_ascii_code())) return true;
+}
+
+
diff --git a/honoka/libhonoka/preeditor.h b/honoka/libhonoka/preeditor.h
index 60dffef..111efd5 100644
--- a/honoka/libhonoka/preeditor.h
+++ b/honoka/libhonoka/preeditor.h
@@ -91,6 +91,7 @@
     virtual void unSelected();
     static const WideString getCommitString();
     static void resetCommitString();
+    static bool isPrintable(KeyEvent &key);
 
 protected:
     static WideString text;